The first money was earmarked for the project in 2007. Design work began in earnest two years ago, when funds actually became available.

The final two options had been winnowed down from five. The three discarded possibilities included two at-grade crossings above and below where the trail intersects Hall Boulevard and a mid-block crossing at the trail's intersection with the roadway.

Numerous public meetings were held to gather opinion about how to proceed. In addition, a committee composed of public and private groups has been meeting to weigh how best to move cyclists and pedestrians across a thoroughfare carrying tens of thousands of cars a day, many barreling along at speeds of 40 mph or more.

Of the two options that emerged from those discussions, the bridge -- or "overpassing" as it's called in official documents -- appeared to have more support.

At a projected cost of $5,006,118, the bridge would feature dual spiral ramps to minimize effects on wetlands on the north side of Hall Boulevard, metal staircases and a maximum gradient of 6.25 percent with landings every 40 feet. Construction would take from four to six months.

The tunnel -- or "undercrossing" -- is much more involved. At a cost of $9,052,061, it would require raising the elevation of the roadway by eight to 10 feet to keep the tunnel's lowest point above the 10-year flood plain. It would feature extensive retaining walls on both sides of the road, but would also allow easier access and use by most people. Construction would take from 12 to 18 months.

No single pot of money exists to actually build either project. Planners hoped to begin design work with money they have in hand, but said it could take several budget cycles to acquire the county, state and federal grants needed to begin construction.

At Tuesday's meeting, several alternative choices were tossed out, meaning some new direction could yet emerge as discussions continue.

John Griffiths, a park district board member, was traveling on business, but submitted written comments. He suggested "punching" a tunnel under Hall Boulevard, even if the bottom of the structure ends up being well below the 10-year flood plain.

Beaverton councilor Marc San Soucie said the feasibility of an at-grade crossing should be re-examined.

No meetings have been scheduled to determine just where the project goes from here, but easy options don't appear to be in the offing.

"We're in a box trying to get out," said Bob Scott, park district board chairman. "We may have to go back to the drawing board."